%VECPLOT routine to plot vectors. % VECPLOT draws vectors on the current figure, at (x,y) % locations determined in one of two ways. If the first % argument to VECPLOT is a fem_grid_struct, then VECPLOT % extracts the FEM domain coordinates as the vector origins. % Otherwise, the user supplies the (x,y) coordinates % explicitly. This flexibility exists because vector % plotting does not require any knowledge of nodal % connectivity, and perhaps the (u,v) data are not % from a FEM model output. % % VECPLOT scales the magnitude of % (u,v) by the magnitude of max(abs(u,v)) and then % forces a vector of magnitude sc to be 10% of the x data % range. By default, sc = 1., so that a 1 m/s vector will % be scaled to 10% of the x data range. If sc=.5, then % a vector magnitude of 50 cm/s will be scaled to 10% of the % x data range. Decreasing sc serves to make the vectors % appear larger. VECPLOT then prompts the user to place % the vector scale on the figure, unless scale_xor,scale_yor % is specified (see below). % % INPUT: fem_grid_struct (from LOADGRID, see FEM_GRID_STRUCT) % OR % x,y - vector origins % u,v - vector amplitudes % These inputs are optional, but if one is needed, all % preceeding it wil be required. % sc - vector scaler; (optional; default = 1.) % sclab - label for vector scale; (optional; default = 'cm/s') % scale_xor,scale_yor - location to place vector scale % % OUTPUT: h - vector of handles to the vector lines drawn, the % scale vector, and the scale vector text. % % NOTES: VECPLOT requires atleast 2 coordinates and vectors. % % CALL: hv=vecplot(x,y,u,v,sc,sclab) % or % hv=vecplot(fem_grid_struct,u,v,sc,sclab) % % Written by : Brian O. Blanton % function retval=vecplot(varargin) % Copy incoming cell array input_cell=varargin; % DEFINE ERROR STRINGS err1=['Invalid number of input arguments to VECPLOT']; err2=['Struct to VECPLOT not a valid FEM_GRID_STRUCT.']; err3=['Length of u,v must be the same']; err4=['Length of (x,y) must equal length of (u,v).']; err5=['Alteast 3 arguments are required if first is a fem_grid_struct.']; err6=['Alteast 4 arguments are required if first two are x,y.']; err7=['Second optional argument (sclab) must be a string.']; err8=['Both x- and y-coords of vector scale must be specified.']; nargs=length(input_cell); % PROCESS THE INPUT ARGUMENTS % Length of input_cell must be between 3 and 8, inclusive. if nargs<3 | nargs>8 error(err1) end % Determine if first cell contents of input_cell is % a struct and if so, is it a valid fem_grid_struct if isstruct(input_cell{1}) % Is the input struct FEM valid? if ~is_valid_struct(input_cell{1}) error(err2) end if nargs<3 error(err5) end % If we're here, the first cell of input_cell is the domain % structure; xin=input_cell{1}.x; yin=input_cell{1}.y; % The second and third cells are u,v uin=input_cell{2};vin=input_cell{3}; % Check lengths of u,v against x if length(uin)~=length(vin) error(err3) end if length(uin)~=length(xin) error(err4) end % delete the cells accounted for so far; the remaining will be % processed below. input_cell(3)=[]; input_cell(2)=[]; input_cell(1)=[]; else % If we're here, the first argument to VECPLOT is NOT % a structure; the first 4 arguments are then required % and are x,y,u,v; there is no way to ensure that the % order is correct. Hopefully, said user read the help text! if nargs<4 error(err6) end xin=input_cell{1};yin=input_cell{2}; uin=input_cell{3};vin=input_cell{4}; % delete the cells accounted for so far; the remaining will be % processed below;. input_cell(4)=[];input_cell(3)=[]; input_cell(2)=[];input_cell(1)=[]; end % At this point, the copy of the input cell has been reduced to % contain the optional arguments, if any. if length(input_cell)==0 sc=1.;sclab=' cm/s'; elseif length(input_cell)==1 sc=input_cell{1}; sclab=' cm/s'; elseif length(input_cell)==2 sc=input_cell{1}; % Make sure second optional arg is char if ~isa(input_cell{2},'char') error(err7) end sclab=[' ' input_cell{2}]; elseif length(input_cell)==3 error(err8) else sc=input_cell{1}; % Make sure second optional arg is char if ~isa(input_cell{2},'char') error(err7) end sclab=[' ' input_cell{2}]; scale_xor=input_cell{3} ; scale_yor=input_cell{4} ; end col='b'; % % save the current value of the current figure's WindowButtonDownFcn, % WindowButtonMotionFcn, and WindowButtonUpFcn % WindowButtonDownFcn=get(gcf,'WindowButtonDownFcn'); WindowButtonMotionFcn=get(gcf,'WindowButtonMotionFcn'); WindowButtonUpFcn=get(gcf,'WindowButtonUpFcn'); set(gcf,'WindowButtonDownFcn',''); set(gcf,'WindowButtonMotionFcn',''); set(gcf,'WindowButtonUpFcn',''); % SCALE VELOCITY DATA TO RENDERED WINDOW SCALE % RLs= get(gca,'XLim'); xr=RLs(2)-RLs(1); X1=RLs(1); X2=RLs(2); RLs= get(gca,'YLim'); yr=RLs(2)-RLs(1); Y1=RLs(1); Y2=RLs(2); % IF RenderLimits NOT SET, USE RANGE OF DATA % if(xr==0|yr==0) error('Axes must have been previously set for VECPLOT2 to work'); end pct10=xr/10; %FILTER DATA THROUGH VIEWING WINDOW % filt=find(xin>=X1&xin<=X2&yin>=Y1&yin<=Y2); x=xin(filt); y=yin(filt); u=uin(filt); v=vin(filt); % SCALE BY MAX VECTOR SIZE IN U AND V % us=u/sc; vs=v/sc; % SCALE TO 10 PERCENT OF X RANGE % us=us*pct10; vs=vs*pct10; % SEND VECTORS TO DRAWVEC ROUTINE % hp=drawvec(x,y,us,vs,25,col); set(hp,'UserData',[xin yin uin vin]); set(hp,'Tag','vectors'); % COLOR LARGEST VECTOR RED %[trash,imax]=max(sqrt(us.*us+vs.*vs)); %hvmax=drawvec(x(imax),y(imax),us(imax),vs(imax),25,'r'); %set(hvmax,'Tag','scalearrow'); % PLACE SCALE WITH MOUSE ON SCREEN % if ~strcmp(blank(sclab),'no scale') ptr=get(gcf,'Pointer'); if ~exist('scale_xor')| ~exist('scale_yor') disp('place scale on plot with a mouse button'); [scale_xor,scale_yor]=ginput(1); end ht1=drawvec(scale_xor,scale_yor,pct10,0.,25,'r'); set(ht1,'Tag','scalearrow'); if strcmp(blank(sclab),'m/s') sctext=[num2str(sc) sclab]; else sctext=[num2str(100*sc) sclab]; end scaletext=text((scale_xor+scale_xor+pct10)/2,scale_yor-(Y2-Y1)*(.05),sctext); set(scaletext,'HorizontalAlignment','center'); set(scaletext,'VerticalAlignment','middle'); set(scaletext,'Tag','scaletext'); set(gcf,'Pointer',ptr); else ht1=[];scaletext=[]; end % OUTPUT IF DESIRED % if nargout==1,retval=[hp ht1 scaletext];,end % % return the saved values of the current figure's WindowButtonDownFcn, % WindowButtonMotionFcn, and WindowButtonUpFcn to the current figure % set(gcf,'WindowButtonDownFcn',WindowButtonDownFcn); set(gcf,'WindowButtonMotionFcn',WindowButtonMotionFcn); set(gcf,'WindowButtonUpFcn',WindowButtonUpFcn); % % Brian O. Blanton % Department of Marine Sciences % 15-1A Venable Hall % CB# 3300 % Uni. of North Carolina % Chapel Hill, NC % 27599-3300 % % 919-962-4466 % blanton@marine.unc.edu % % SUMMER 1998 %